Thread clamping device



June 15, 1965 Filed March 6, 1961 w. MAYER ETAL 3,188,835

THREAD CLAMPING DEVICE 2 Sheets-Sheet 1 2 i HIM I F I -L. 1a

6" WERNER- MAYER EWALD HANEL ATTORN June 15, 1965 w. MAYER ETAL 3,

THREAD CLAMPING DEVICE Filed March 6, 1961 2 Sheets-Sheet 2 WERNER M,4YER [WALD HANEL BYBLLLT 55 D -King)? 5p! ATTORN 5 3 Claims. (:1. 66-145)The present invention relates to a thread clamping device, and moreparticularly to a combined suction and clamping device for securingthread during knitting operations in circular knitting and straight barknitting machines.

Various thread clamping devices are known, which are generally used inconnection with mechanical or electrical cutting devices for separatingthe threads from the articles being knitted at the end of a course ofknitting (see. US Patents 2,908,154 and 2,924,958). The cutting deviceis normally placed at a point in the thread path between the articlebeing knitted and the clamp device which serves to hold the thread endafter cutting. The clamping device is positioned in the vicinity of thethread guide or feed means at the point in the knitting where theclamping and cutting is to take place. In particular, circular knittingmachines cannot readily accommodate clamping and cutting devices for theknitting thread or yarn since such knitting machines are provided withcylinders of comparatively small diameters wherein several knittingsystems or stations are utilized for producing, for example, fineseamless hose. Moreover, it will be appreciated that in the usualstraight bar I knitting machines, space for accommodating said clampingand cutting devices is very limited as well (see US. Patents 2,844,016and 2,863,310).

It is conventional to provide a suction pipe or nozzle for drawing 01fthe thread ends by suitable suction upon the cutting of the thread atthe end of a course of knitting. The suction pipe is generallypositioned between the cutting device and the clamping device.Nevertheless, because of the relatively small distance between thesuction pipe nozzle and the cutting device, Which ismade necessary bythe lack of sufiicient space in the machine, the resulting thread endsupon cutting of the same by the cutting device are so short and stiiIthat they cannot be readily retained with any degree of efiiciency bythe air current generated by the suction pipe. Additionally, as is thecase where electrical cutting or separating means are employed, such asfor the cutting of synthetic or thermoplastic thread or yarn, theheating element, i.e. an electrical resistance Wire, is strongly cooleddue to the continuous air current of the suction pipe positioned soclosely thereto. Naturally, the greatest cooling effect is noticed atthe outermost portion of the heated resistance Wire or element, which inany case is much harder to keep heated to the desired temperature thanwould be the remainder of the electrically heated resistance wire orelectrical separator means.

It is an object of the present invention to overcome the foregoingdrawbacks and to provide an apparatus for the efiicient, clamping of thethread used in circular knitting and straight bar knitting machines,such device being utilizable together with a cutting device.

Other and further objects of the invention will become apparent from astudy of the within specification and accompanying drawings in which,

FIGURE 1 is a schematic partial perspective view of a portion of acircular knitting machine of conventional design illustrating theposition relationship of the thread 1 United States Patent 3,188,835Patented June 15, 1965 guide, cutting element, and thread clampingdevice of the invention,

FIGURE 2 illustrates schematically a partial perspective view of astraight bar knitting machine of conventional design provided with acutting element, thread guide, and alternate embodiment of the threadclamping device of the invention,

FIGURE 3 illustrates a schematic partial sectional view of a threadclamping device in accordance with the invention similar to that shownin FIGURE 2 containing a modification for looping the thread retained bythe device of the invention,

FIGURE 4 illustrates a schematic partial sectional view of the topportion of the thread clamping device of the invention 'as illustratedin FIGURE 3, and

FIGURES 5 and 6 are further schematic perspective views illustrating thewithdrawing and inserting of the thread guide out of and into activefeeding position.

In accordance with the present invention, it has been found that athread clamping device for securing thread ends during knittingoperations in circular knitting and straight bar knitting machines maybe provided which comprises suction nozzle means and thread engagingsurface means arranged in the path of the knitting thread for relativemovement from a position out of thread clamping contact to a positioninto thread clamping contact with one anotherj The suction nozzle meanspreferablyincludes, in .accordance with one embodiment of the invention,used in connection with a circular knitting machine of the dial type, atubular suction nozzle member positioned in spaced relation to andcompletely out of contact with the dial cap and a tubular extensionmember, such members being concentrically positioned for telescopicmovement with respect to one another. In this manner, the extensionmember may be extended into and Withdrawn out of clamping contact withthe surface means. Conveniently, the extension member outwardly enclosesand is axially slidably upon the nozzle member, and the extension memheris preferably provided with an elastic end rim for engaging thread whensuch rim is extended into clamping contact with the surface means. Theextension member, for efiicient operation, is normally resiliently urgedinto extended position for suitable thread clamping contact. The urgingmay be effected by means of a loaded coil spring disposed about thenozzle member and secured thereto at one end, the other end of thespring abutting the extension member for forcing the same into threadclamping contact with the surface means.

To actuate the extension member, for axial movement into and out ofthread clamping contact, a draw rod may be connected to the extensionmember at one end and coupled with a suitable pattern device at theother end which causes the desired actuation to take place during theknitting operation.

A suitable pattern device, for example, may take the form of a guide camring concentrically disposed with respect to the cylinder, as will bemore fully appreciated from copending US. application Serial No. 42,355,filed July 12, 1960, wherein a contact ring or guide cam ring for thecontrol of thread guides is mounted for limited rotational movement inresponse to a cam drum or pattern drum linkage, such as that shown inBritish Patent No. 810,225. With respect to the instant case, such guidecam ring may be provided with an upper cam surface thereon which isfollowed by a follower portion of the draw-rod. Upon suitable actuationof the guide cam ring, the draw-rod will be axially displaced formovement of the extension member into and out of clamping contact Withthe surface means. If desired, the pattern device may be provided foraxially displacing the drawrod once during each cylinder rotation, asfor example a clamping.

would be the casein the knitting of a reinforcement thread into areinforcement portion ofthe hose or tubular fabric article beingknitted. One construction of actuation meansfor axially displacing thedraw-rod once for each cylinder. revolution .-is described in detail incopending;U.S. application filed simultaneouslyherewith, it Serial No.93,804, filed'Mareh 6, 1961, entitled Thread Changing Apparatus Ofcourse, the pattern device in-,

steadmay includea'simple pattern drum .which rotates at the same rate asthe circular knitting machine, in connection with which the device maybe used, such that clamping contact will be made once during eachcylinder Various control cam devices of the forea y revolution. goingtype are well known and are indicated, for example, in U.S. Patent No.2,908,154 and British Patent No. 810,225., p j

On the other hand, where used with a straight bar knitting-machine, asuitable timing device may actuate the clamping means into and out ofclamping engagement as for example when the yarn or thread being knittedis removed from knitting action at the end of the last vknitting courseto be knitted therewith, such as where the thread guide reaches the endof the needle bed. The

I for cutting the thread for example after threadclamping contact .hasbeen achieved between thesuction nozzle means and the thread engagingsurface means:

Where the thread clamping device is used in connection with a circularknitting machine, the thread engaging t a 4 i As is specifically thecase with straight bar knitting machines of conventional design having,a bed of knitting elements, the suction nozzle means may bestationarily positioned at the end of'the bed with a' thread cuttingelement disposed-adjacent the cover surface between the end of the bedand the suction nozzle means. Suitably; the cutting elementandcoversurface'are mounted on a' shaft for movement. across the pathof'the thread" to be clamped. f These elements are aligned atv the endof the bed so that they will be first: actuated away from the threadpath before the thread guide carrying the thread therealong passes'toinactiveknitting position.

back across the thread path. .Since the cover surface is positioned moreforward than the cutting" element,'the cover surface will engage thethread and move'the same intothread clamping contactwith the suctionnozzle means before .the thread will be cut by the cutting element. i V7 An. electrical resistance wire heating element of conventional designis normally'used for effecting the cutting of the-thread after clampinghas been achieved. (See U.S.- Patents 2,844,016 and 2,863,310.)

It is apparent therefore that in accordance with the present invention,the clamping of the thread 'is carried out. by the opening or rim end ofthe suction nozzle means together witha thread engaging surface meansmovable into thread clampingrelationtherewith, Be-

cause of the advantageous covering over of the suction nozzle meansduring clamping, no cooling air current i will flow whichwould-otherwise.undesirably cool the electrical resistance wire cuttingelement. Not. only is 'the avoidance of unnecessary cooling oftheelectrical cutting element attained but also a saving in thegensurfacemeans is conveniently definedby the top surface ofthe stationary dialcap so that clamping contact is effected by moving the extension memberfrom withdrawn or opened position into contact with the top surface ofsuch'dial cap, i.e. to closed position. In this con nection, a threadcutting elment is preferablypositioned on the dial cap and the threadguide is positioned adjacent the dial cap at the point where threadcutting is to take place. The tubular extension member is thuspositioned between the thread guide and cutting element for extensioninto clamping contact with the dial cap. This occurs where the path ofthe thread being knitted by the machine 'is situated intermediate thewithdrawn tubular extension member and the dial cap so as to permitthe'desired Alternatively, and especially where the device of theinvention is used in connection with straight bar knitting machines, thethread engaging surface means is defined asa cover surface adapted t oseal off the; suction nozzle means when thread clamping contact isachieved.

eration of suction through the nozzle means passage. Moreover, theinterruption of. the suction air current during thread clamping contactmay result in the need for less expensive suction equipment or theapplication of present'equi'pment for a greater numberof suction nozzlemeans.' .7

The elastic material suitablyprovided on at'least one of the threadclamping members for engaging the thread to be clamped, may be intheform of rubber, resilient or-soft synthetic, plastic, or other resilientor soft material permittmg-asure grasp of the thread and a suitablesealing ofl? of the air curren-t passing through the suction nozzlemeans. a

Naturally,.where the thread engaging projection means insertable withinthe suction nozzle rneans is present, long thread ends maybe retained bythe suction nozzle means f of the thread clamping device even where theoperative elements have been withdrawn from .thread clamping thisinstance, the suction nozzle'means need not'be provided with a tubularextension, but instead contact is achieved by pivotal movement of thecover surface into clamping engagement with the .end rim oredge ofthesuction nozzle means. Suitably, the cover surface is provided with anelastic portion disposed thereon for achieving sealing engagement withthe suction nozzle means while clamping thread therebetween; V

In accordance with a preferred modification of the invention, thecover'surface is provided with a thread en-' knitting machines.

' contact. Because a long thread end is present ,as compared'with thediameter of theopening of the nozzle 7 means, the thread'end will bereliably held by suotion when clamping contact ceases.

'Advantageously, this feature 1s provided even though the threadseparator or electrical resistance wire cutting means, is relativelyclosely positioned. to the thread-clamping means of the invention as isparticularly the case 'with straight bar It willbe particularlyappreciated that the present invention represents an-improvement incircular knitting machines having means for forming knitted patternareas in Va 'tubular. fabric,'-for example, such machine including aneedle cylinder, needles disposed in said cylinder,

gaging projection means insertable into the suctionjnozzle means,passage duringv the threadrclampingcontact. The projection meansisadapted toengage the thread-to be clamped, and in this manner carry aportion thereof into. the suction nozzle meansv passage upon the threadclarnpingcontact so' as toform a loop portion in the thread. 7 a

elements cooperating with the needleslfor formationofstitches,-ca-msforfefiecting needle. movement, yarn feedmg or guidemeans movable from an active yarnfeeding position whereinyarn is fed tothe needles for 'knitting jthereby to an inactive yarn feeding position--,wherein the yarn,1s in non-knitting p0si-tion,- and means forclamping and cuttingi the yarn when the yarn feeding means is in activeyarn feeding position and forreleasing the yarn when the yarn feedingmeans is moved to active Once the thread or yarn hasipassed, the'shaftis next actuated yarn feeding position. The improvement of theinvention generally comprises a combined thread clamping and suctiondevice including suction nozzle means and thread engaging surface meanswhich are arranged for relative movement from a position out of threadclamping contact to a position into thread clamping contact with respectto one another when the yarn feeding means or thread guide is in activeyarn feeding position. The thread clamping device of the invention, ofcourse, is readily usable together with a closely positioned threadseparating or cutting device, since the improvement of the invention isdirected to the more efficient clamping and cut-ting of thread inrelatively confined spaces than could be achieved heretofore.

With respect to the drawings, FIGURE 1 shows a portion of a conventionalcircular knitting machine having a cylinder rotating in the direction ofthe arrow P, said cylinder being provided with a needle bed having aplurality of needles N axially disposed in slots therein in theconventional manner.

As is customary in circular knitting machines for the production ofseamless fine hose, the cylinder is provided with the normal dial 6' forthe slidable reception of the transfer bits (one of which isschematically shown at 6"), dial 6' being positioned over the top end ofthe cylinder. Disposed above the dial 6 is a dial cap 6 which isstationary. Dial cap 6 is provided with a thread separator 5 which maybe an electrical resistance wire doubled back on itself to form avertical heating element maintained at a temperature suflicient to severthe particular yarn or thread used, i.e. nylon, etc.

Disposed immediately above dial cap 6 in spaced relation thereto andcompletely out of contact therewith is tubular suction member 1connected with a vacuum or other source of suction remote from thecircular knitting machine. Extension piece 2 is telescopically slidableon suction nozzle member 1 and is normally urged in downward directionby coil spring 3 attached at its upper end to suction nozzle 1 by meansof a collar 4 and positioned in urging abut-ment with the top edge ofextension piece 2. Extension piece 2 is suitably provided along itslower edge or rim portion with an elastic covering 21 made of rubber,for example, which forms the surface against which the thread P will besecured. Draw rod 7 controls the axial movement of extension piece 2with respect to suction nozzle 1 so that the extension piece 2 may beurged by spring 3 into thread clamping engagement with the top surfaceof stationary dial cap 6. Drawrod 7 may be suitably connected with apattern device such as a pattern drum D rotating at the same rate as thecylinder or any other control means as aforesaid so as to causedisplacement of draw-rod 7, as for example, once during each rotation ofthe cylinder.

In this way, where the needles are suitably actuated in the usual way,by cam means within a certain portion .of the circumference of thecylinder as may be the case, for example, in adding a reinforcementthread or yarn to be knitted along only a portion of the knittedarticle, such as is the case with rein-forced soles and heels of finehose, the thread guide or thread feeding means 8 may be lowered intoactive position immediately adjacent the needles N in any suitablemanner, such as by rotating cam E or .by the afore-described means setforth in said co-pending US. application Serial No. 42,355. The

first needle of that portion of the cylinder needles to be actuated, asby suitable activating cam means, for the knitting of the reinforcementportion of the hose, therefore, will be raised into the path of thread Fsince thread guide 8 has been downwardly displaced into active knittingfeed position across the needle path. The thread Fmay now be knitted inthe normal manner until the knitting course recahes the last needle ofthat portion of the needles of the cylinder used to knit thereinforcement portion of the hose. When this occurs, thread guide 8 willbe suitably upwardly displaced out of active thread feeding position bysuitable control means as aforesaid, whereupon the last needle N of thesaid portion will remain in engagement with the thread F and carry thesame in the direction of the arrow P around the cylinder therewith. Whenthe last needle N passes a certain point, the thread P will be disposedalong dial cap 6 directly beneath extension piece 2, extension piece 2having been upwardly displaced in the meanwhile to permit the thread Fto pass directly therebeneath, for example at about the same time thatthread guide 8 is upwardly displaced out of active knitting position.Then, extension piece 2 is once more downwardly urged into threadclamping contact with dial cap 6 retaining the thread F securely. Atthis time, as the said last needle N passes around the cylindercircumference, the thread will abut the then electrically energizedthread separator 5 whereupon the thread will be severed leaving only asmall end in the reinforcement portion of the hose being knitted, yetleaving a suitably long end portion of the thread F which will beeffectively retained by the thread clamping means and especially byextension piece 2, even after the same is next raised from threadclamping contact, due to the suction provided upon raising.

It will be appreciated that during knitting operations, normallyextension piece 2 will remain in abutment with dial cap 6 to prevent theundesired passage of suction air current upwardly through extensionpiece 2 and suction nozzle member 1. The undesired cooling of electricalresistance wire heating element 5 will, therefore, be prevented.

Thus, where the first needle of the needles to be used for knitting thereinforcement portion of the hose comes into engagement with theactivating cam means therefor, which may be stationarily positionedwhile the cylinder containing the needles rotates therepast, suitablepreselected needle butts on these needles will be urged by the cam meansin upward direction just after the thread guide 8 has been downwardlydisplaced. Stated another way, the thread guide 8 will have beenswitched to activated position just prior to the passage of the firstreinforcement needle therepast. The extension piece 2 remains inclamping engagement with dial cap 6 during this time. Of course,suit-able pattern devices may be used to control the timing of thelowering and raising of thread guide 8 into and out of active knittingposition which may be carried out in accordance with the aforesaid camring displacement arrangement disclosed in said co-pending U.S.application Serial No. 42,355.

Specifically, a pattern drum may be opera-tively connected by suitablelinkage means to actuate cam ring means for lowering and raising threadguide 8, which drum revolves in dependence upon the rate of revolutionof the knitting cylinder or independent thereof as the case may be.Consequently, thread guide 8 will be inserted into active feedingposition across the knitting needle path before the first needle to beemployed for knitting the particular yarn or thread passes that point.This first needle, as aforesaid, may be the first needle of that portionof the needles along the cylinder circumference used for knitting thereinforcement portion of the hose.

In accordance with the preferred operation of the invention, the firstneedle of said portion of needles will be actuated for knitting by thecam means directly adjacent the position of thread guide 3, while thethread end extending therefrom to the extension piece 2 will be carriedalong by said first needle to a point adjacent the location of threadseparator 5, whereby severing of this thread end will occur close to thefirst stitch. In this manner, the thread end held by the thread clampingdevice will be brought into contact with thread separator 5 cutting offsuch thread end and allowing the same to be retained by suction nozzlemember 1 until extension piece 2 is next raised. The other end of thethread in the course being knitted will be desirably short in length sothat a minimum of thread ends will occur in the knitting of thereinforce-z.

ment portion. I

In turn, when the last'needle passes thread guide in V the direction ofthe arrow P, the control of thread guide 8 is such that the same will beupwardly displaced out of active feeding position. Nevertheless, thelast knitting needle will carry the thread F along the path of movementof such needle a certain dist-ance whereupon 'a similarcounter-clockwise, as viewed inthe drawing, cover plate 12 will'clam'pingly engage thread E against the nozzle a rim of suctionnozzlemeans '1 before separator-element 5' comes into contact with the thread.I I I A suitable control mechanism may be provided which may be timed tobe actuated, to pivot shaft 13 in the pat-tern device such as a patterndrum will have caused draw rod 7 to be upwardly displaced alsodisplacing extending piece 2. The already cut thread end will now passthrough nozzle member 1. The thread F will pass di- 7 rectly beneathextension piece 2 as it is carried by the'last needletow-ard threadseparator 5.- Aftera suitable move- I I ment of upwarddisplacement,extension piece 2 Will have i been once again downwardly urgedbydr'aw-rod 7 in consequence of the control means used, ie a patterndrum or the like. ,The thread continuesv to move with'the I last needleuntil the same abuts the thread cutter or be readily retained by 2even'when said extension piece is next raised, due to the air, suctionthrough suction nozzle member 1.

Of course, alternatively, extension piece 2 may be kept in raisedposition untilafiter thread F has been'severed by separator 5 so thatthe thread end extending from extended position of member 2 into contactwith dial 'cap 6..

Normally, extension piece 2 is'raised once during each placed'in'engag'ement with nozzle meansl' to tseal of]? desired forwarddirection "as shown the arrows just after thread guide 8' whichis beingwithdrawn from active knitting'position has passed the nozzle 1' alongthercourse of movementthereof with respect to the sinker head 14.Naturally, it;is preferred to resiliently mount lever 9 on shaft 13 sothat upon contact between the 'nozzlerim of suction nozzle 1' andcoverplate 12, shaft 13 may be. turned even further'acertain incrementto allow thread separator 5" to comeginto contact with the thread F.'Upon the'return movement of thread' guide 8"back into activeknittin'glpos'ition, a suitable control inay-urg'e shaft 13 in reversedirection so as to withdraw cover plate 12 and separator element 5 fromthe path of thread F. Nevertheless, cover plate 12 may be again suctionby forward movement ofgshaft I3 a certain increment so that thread guide8' may proceed with the further knitting in opposite direction withoutthe'thread ;30 thread guide 8 will be drawn by suction into nozzlemern-:. her 1 and retained thereatin raised positlon as well as inrevolution of the cylinder since this is only needed to permi t thethread to be clamped at theend of theknltting of I 1 I a course of thereinforcement portionof thehose, Even so, the extension piece 2 may beraised after the start of a the knitting of the next level or course ofstitches of the reinforcement portion upon the severing of the portlonof thread held by the clamping meansfrom the new thread to be knitted,so that the thread end severed by thread separator 5 may be withdrawnthrough suction nozzle 7 member 1. Of course, such removalmay await theaforesaid raising of extension piece 2 at the cuttingofthe thread at theend'of reinforcementportion whereby the being severed by separatorelement 5.; I I

If desired, once the knitting in the opposite direction has started,suitable further forward actuation of shaft 13 may occur due'to theresilient mounting of lever 9 upon shaft 13, so that separator element-5' is once more brought'into contact with/the end'of thread F betweenthe needle bar' and-the-nozzlemeans 1'. In this manner,

.only short thread ends. will remain along the edge of the fabric. 'Whenthreadguide 8' completes a further knitting operatiomfit is once morepassed in the return direction towards separator 5'. Shaft 13 may besuitably actuated to withdraw separator '5? and disengage cover plate"12 from 'the'rim of nozzlemeans 1" whereby the passage of threadtherealong is facilitated The cycle may then be repeated. iSpecifically, in operation, for example, when the production of thedouble edge or turned welt portion, of the already cut piece may bewithdrawn through. suction",

nozzle member 1 at that time.

With respect to-FIGURE 2,"a conventionalistraight bar knitting machineis shown having'a bed of needles N and a cooperating bed of sinkersSalong the center bed 15. A thread guide 8' is, disposed in theconventional manner fo'r'passage along thev needles .and sinkers for theusual knitting procedure; At the end of the machine, when aparticularknitting operationhas been completed with respect to thread guide 8',the thread E is normally severed by a cutting or separating element 5'.

In accordance with the present invention a suction nozzle means 1'isdisposed'directlyadjacent the path of movement of the thread 'Fcarried'by thread guide. 8' along,

the course of the sinker head 14; In this instance, a lever 9 isdisposed on a pivotable shaft '13, said lever-having a'cover plate 12provided witha'suitable elastic cover- 7 ing 11 formed ofjrubber-or thelike. Also disposed on I knitted article l as be'en completed, andanother thread guideis'to beinsertedintoactivethread feeding position, acontrolflinkage including a conventional pattern drum arrangement orother conventional means *(se e 'U.S.

Patents -2,844,016"and 2,863,310) may causej'the withdrawing of thread,guide 8 from active knitting position to -the inactivepositionshown inFIGURE 2. The thread guide 8 will remain 'in the inactive position shownin FIGURE 2 'until nextactuated' However, prior to the withdrawing ofthread guide 8' to the position shown inFIGURE 2, shaft 13is rotatedanincrer'nent in clockwise'directionso that cover plate 12 and separatorelement 5' will berearwardlyurged out shaft 13 is'the conventionalcutting element 5', which may take theform of an electri cal-resistanceelement which is heated to a high enough'temperature to effect thesevering of the thread or yar n F. While both lever j 9 and threadseparator or cutting element 5' are disposed for movement on a'commonshaft 13, cover plate"12 will' of ,thepath of "thread guide 8',to vtheposition shown inFIGURE 2. When thread guide 8'* has reached in activeposition, shaft 13, may be forwardly rotated, so

that thethread F willbe cla'rnpedby cover plate 12 and nozzle means 1"will be sealed. Upon further forward (counterclockwise) rotation ofshaft 13,"separator'eleme'nt 5' wi ll sever the thread F close to thefabric edge. Coverplate 12 will retain thethread end extending from:thread guide 8' thereto. When threadguide 8' is again to be placedinactive knitting position, shaft 13 again rotates in clockwise.direction; withdrawing cover plate 12 and separator element S'fromIthethread path, and

allowing the previously severed thread end extending fromthread guide 8to the nozzle means 1 to;be drawn be positioned with respect to saidshaft at a point closer to the path of thread Fthan that of separatorelements,

In this manner, uponfpivoting shaft 13 to the left or by suction intothe nozzle rneans l. After thread guide '8? has passed thereby'an'dbecome engaged once more inactive knitting of thread E, shaft '13. maybe conveniently rotated in counterclockwise direction again to cause thecovering of nozzle'means 1 by cover plate 12 and thereafterthef'severing of the thread between nozzle means '1' .andthe fabric edgebyeIementS'. The severed end of thread held between nozzle means 1' andcover plate 12 will be drawn off by suction through nozzle means 1 thenext time cover plate 12 is withdrawn from clamping contact. The cyclemay then be repeated.

It will be appreciated that shaft 13 may be duly actuated in the desiredsequence in dependence upon a control linkage to a pattern drum in theconventional manner (see US. Patents 2,844,016 and 2,863,310).

FIGURES 3 and 4 illustrate the modification wherein a thread engagingprojection 16 comprising a wire loop having an inwardly directed arcuateportion is disposed on cover plate 12. Projection 16 will, therefore,engage the thread F by the inwardly arcuate portion and force the threadwithin nozzle means 1 when lever 9 is pivoted in forward direction withcover plate 12 being placed in clamping engagement with the nozzle endof nozzle means 1. A suitable length of the thread F will, therefore, bedrawn so as to ensure a retention of the thread end even when coverplate 12 is withdrawn from clamping engagement with the end of nozzlemeans 1. It will be appreciated in this connection that by means of theprojection 16, a sufliciently long piece of thread may be provided asdesired, even though the suction nozzle means and thread clamping deviceof the invention are placed immediately adjacent the thread cutting orseparator element 5' because of the restricted space for maintainingthese working elements.

In accordance with the present invention, it will be appreciated thatwhere desired cover plate 12 may be formed instead as a ring to permitclamping yet allow the passage of suction air into and through thenozzle opening.

To more clearly illustrate the preferred manner and sequence ofWithdrawing and inserting the thread guide means from an inactive yarnfeeding position where the yarn is in non-knitting position to an activeyarn feeding position wherein the yarn is fed to the needles forknitting thereby, FIGURES 5 and 6 are included. These figures show theinvention as applied to a circular knitting machine and indicates thatthe clamping means of the invention and the cutting means for the yarnor thread may advantageously both operate when the yarn feeding means orthread guide 8a is moved to inactive yarn feeding position, whereas whenthe thread guide 8a is moved to active yarn feeding position, theclamping means may remain closed while the cutting means alone willoperate.

Accordingly, as shown in FIGURE 5, the cylinder needles N rotate withthe cylinder in the direction of arrow P.- When the last needle whichshould take the yarn of the thread guide 8a, i.e. the reinforcementportion of the hose, for example, has passed thread guide 8a, a suitablecontrol coupled with the rotation of the cylinder, for example such as apattern drum, causes movement of thread guide 8a towards the center axisof the rotating cylinder of the circular knitting machine. At about thesame time, draw-rod 7upwardly displaces extension piece 2 so that thelast needle which engages a thread will carry the same therewith alongthe cylinder circumference in the direction of arrow P. This needlepasses through positions N, N N N N The path of movement of the threadduring this time is illustrated schematically in dotted line such thatthe thread will be disposed directly beneath extension piece 2 by thetime the same comes into contact with the thread separator 5. Draw-rod 7may now be suitably actuated to permit thread clamping engagement betwenstationary cover plate 6 and extension piece 2. Once the thread abutsseparator 5, it will be severed leaving only a short thread end at theterminal edge of the reinforcement portion of the course being knitted.The other end will be suitably drawn by suction into extension piece 2and retained by extension piece 2 and dial cap 6 until after the threadguide 8a has next been switched into active yarn feeding position and isagain switched to inactive position. The cycle is then repeated,extension piece 2 being raised, the previously severed thread-end beingdrawn off by suction through nozzle member 1, the new thread once morepassing directly beneath extension piece 2, extension piece 2 beinglowered again and the thread again severed by separator 5 as indicatedin FIG- URE 5.

The control of inward movement of thread guide 8a may be carried out bymeans of rod 8b operatively linked with a pattern drum as mentionedabove such that with each revolution of needle N, thread guide Set willbe inwardly displaced just as needle N travels therepast in thedirection of arrow P. A similar pattern drum or other device may be usedto lift extension piece 2 from normal engagement with cover plate 6 justas thread guide 8a is inwardly displaced, but in this case only untilthe thread passes directly therebetween whereupon extension piece 2 willbe allowed to be lowered once again into clamping engagement.

Concerning FIGURE 6, the initial needle of that portion of needles onthe cylinder used for the knitting of the reinforcement portion of thehose is designated needle N,,. This needle is actuated in the normalmanner for knitting, but before the same has passed thread guide 80,suitable control by means of said pattern drum, for example, causes suchthread guide 8:: to be outwardly displaced away from the center of thecylinder. The thread thus passes the path of needle N, whereupon thethread is carried with the initial needle in the direction of arrow P,executing the positions N N N N The position of the thread in thisconnection is schematically designated by dotted line. The free end ofthe thread during this movement is retained by extension piece 2 whichis normally urgingly in engagement with cover plate 6. When the threadtouches the separator element 5, the thread end is cut e.g. at theinitial edge of the reinforcement portion of the hose such that thisedge will have only very small thread ends due to the close positioningof the needles and the separator element. The knitting is carried out inthe normal manner during this time. The separated end of thread will besimply drawn by suction into extension piece 2 and nozzle member 1 assoon as extension piece 2 is next raised. The actuation of rod 8b inreverse direction to displace thread guide outwardly with respect to thecenter of the cylinder as aforesaid is suitably controlled by thepattern drum. For example, this may operate at the same rate as thecylinder speed of rotation where a reinforcement thread is to be knittedalonga portion of each knitting course of the main thread, so that eachcycle of the cylinder and the drum coincide for the desired controlmovements.

Of course, where the thread guide 8a and the extension piece 2 areassigned for use during the knitting of hose in the normal manner, thethread guide 8a will be switched at first into active yarn feedingposition. The extension piece 2 will not be raised once during eachcylinder rotation but instead will be normally disposed in clampingcontact with dial cap 6 while the knitting of the main coursesprogresses, and correspondingly, the thread guide 8a will remain inactive position throughout. When the main thread used for this purposeis to be Withdrawn from active knitting position at the termination ofthe knitting with this thread, then the thread guide 8a will be switchedout of active position and extension piece 2 will be raised to permitthe thread to pass therebeneath for clamping. Thereafter, the thread maybe conveniently severed by separator 5, the thread end drawn into nozzlemember 1 and clamping once more effected.

It will be appreciated, therefore, that in the initiating of theknitting of a thread in the ordinary case thread guide So will be movedinto acitve yarn feeding position (FIGURE 6) and separator 5 will beenergized although extension piece 2 will remain in clamping contactwith dial cap 6, whereas in the terminating of the knitting of thethread, not only will thread guide 3a be moved 3,188, see

back to inactive position (FIGURES) but also extension piece 2 will beraised for thread clamping prior to severing of the thread end byenergized separator 5 at the terminal edge of the last'aknitted course.

The artisan, of course, will be aware that when several knitting systemsare carried out simultaneously, using multiple knitting stations, athread clamping device in accordance with the inventionyaccompanied by asuitable thread separator element and thread guide may also be used ateach station as desired. 1

It should be noted that whilethe particular thread clamping device isassigned to a thread guide 'or yarn feed'means 8 for the reinforcementthread F to be knitted into the tubular hose or other knitted goodsalong a particular portion thereof during each knitting course,

the normal knittingof the hose'will be simultaneously carried out at aknitting station other than that for" knitting the aforesaidreinforcement portion. Suitable con vention-al needle activating cammeans may be employed for the separate knitting of the main thread'andthe separate knitting of the reinforcement'thread' F, said ventiona-lseparatorelement to clamp and cut the main thread being knitted when"the 1 knitting operation" with such threadis to be terminatedgasmore'fullyappears from the copending application filed simultaneouslyherewith, Serial No. 93,8 04,filed March 6,1961, entitled:

Thread Changing Apparatus;

Whatis claimed is; i 1. In a straight bar knitting machine havingknitting elements, yarn feeding means movable from an active yarnfeeding position wherein yarn is fed to said knitting elements forknitting thereby to an in-active yarn feeding positionwh erein the yarnis-in non-knitting yarn feeding position wherein "yarnisi fed to saidknitting elements for knitting thereby toan inactive yarn feedingposition wherein. the yarn is in non-knitting position, and means forclamping and cutting said yarn when said yarn feeding means is'in activeyarn feeding positioniand for releasing said yarnwhen said yarn feedingmeans is moved to active yarn feeding position, the improvement whichcomprises a'combinedyarn clamping and suction deviceincluding suctionnozzle means andyarn engaging surface means arrangedforrelative movement"from a position out of 'yarnfclamping to a position intoyarn clampingcontact with one-another when yarn feeding means is moved to inactiveyarn feeding position, said yarn feeding means being positionedito movefrom active to inactiveyarn feeding position 'along a path between tsaid nozzle means and surface meanswhen saidnozzle means andsurfacemeans are in open positionout of yarn clamping contact, whereby said'feeding means passes 'main' thread of the hose, being operablewith thecon- 1 position, and means for'clamping and cutting said-yarn when saidyarn feedingtmeans is inactiveyarn feeding position and for releasingsaid yarn when said yarn feeding'means is moved'toactive yarn feedingposition,

the improvement which comprises a combined yarn clamping and suctiondevice including suction nozzle I means and yarn engaging surface meansarranged for:

relative movement from a position out' of yarn clamping contact to aposition into yarn clamping contact with one another when saidyarnfeeding means is moved to inactive yarn feeding position, *saidsurface means being provided with yarn engaging projection meansinsertable 9 into said suctionnozzle means during the yarn clampingcontact, said projection means being adapted to engage the yarn to beclamped and carry a portion. thereof into 7 across the nozzle opening ofsaid nozzle means to permit the yarn to extend; across such nozzleopening and be clamped thereat when said nozzle means andf surface meansare moved to closed position in clamping contact with one anothensaidyarn engaging surface means being a cover surface adapted to seal offsaid suction nozzle means when in yarn clamping contact therewith.

3. Improvement according' to claim 2 'wherein said cover surface isprovided withan elastic portion disposed thereon for sea-lingly engagingsaidsuction nozzlejmeans while clamping Iyarn therebetween.

References Cited by the Examiner UNITED STATES PATENTS 1,727,784 a 9/29Pulster 66-145 2,318,743 7 5/43 Brown 139-256 2,560,484. 7/51 Schoensteret'al. 66-145 2,567,540 9/51 Bergstrom et a1; z 139-256 2,743,877 5/56Fiirst' 139-256.1.X 2,769,599 11/56 Fiirst 242-356 2,810,280 10/57Rossman 66-145 X 2,824,436 2/58 Stack etal. 66-140 2,844,016. 7/58v'Cobert".; 66-145 X 2,863,310 12/58 Miller 66-145 2,908,154; 10/59,ButlerI. 66-140 2,924,958: 2/60 Moyer, 66-140 2,956,593: a 10/60"Bauman'n" .Q 139-257 2,989,935 6/61' Butler 66-145 X 3,019,628 2/62 Page.66- 3,059,867,.10/62' Fiirst 242-356 3,067,778 12/62 fMerki 139-2573,079,779 3/63 Butler et al. 66-14-5 3,120,747 2/64 Reading"; 66-1454FOREIGN PATENTS I 1 810,225 *3/59 GreatBritain.

PARKER, Primary Examiner.

RUSSELL c. MADER, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.5,188,835 June 15, 1965 Werner Mayer et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 9, line 40, for "indicates" read indicate column 11, line 26, for"opreation" read operation column 12, line 5, for "active" read inactiveline 12, before "yarn" insert said I Signed and sealed this 21st day ofDecember 1965.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner ofPatents

1. IN A STRAIGHT BAR KNITTING MACHINE HAVING KNITTING ELEMENTS, YARNFEEDING MEANS MOVABLE FROM AN ACTIVE YARN FEEDING POSITION WHEREIN YARNIS FED TO SAID KNITTING ELEMENTS FOR KNITTING THEREBY TO AN INACTIVEYARN FEEDING POSITION WHEREIN THE HARN IS IN NON-KNITTING POSITION, ANDMEANS FOR CLAMPING AND CUTTING SAID YARN WHEN SAID YARN FEEDING MEANS ISINACTIVE YARN FEEDING POSITION AND FOR RELEASING SAID YARN WHEN SAIDYARN FEEDING MEANS IS MOVED TO ACTIVE YARN FEEDING POSITION, THEIMPROVEMENT WHICH COMPRISES A COMBINED YARN CLAMPING AND SUCTION DEVICEINCLUDING SUCTION NOZZLE MEANS AND YARN ENGAGING SURFACE MEANS ARRANGEDFOR RELATIVE MOVEMENT FROM A POSITION OUT OF YARN CLAMPING CONTACT TO APOSITION INTO YARN CLAMPING CONTACT WITH ONE ANOTHER WHEN SAID YARNFEEDING MEANS IS MOVED TO INACTIVE YARN FEEDING POSITION, SAID SURFACEMEANS BEING PROVIDED WITH YARN ENGAGING PROJECTION MEANS INSERTABLE INTOSAID SUCTION NOZZLE MEANS DURING THE YARN CLAMPING CONTACT, SAIDPROJECTION MEANS BEING ADAPTED TO ENGAGE THE YARN TO BE CLAMPED ANDCARRY A PORTION THEREOF INTO SAID SUCTION NOZZLE MEANS THEREWITH UPONYARN CLAMPING CONTACT WHEREBY TO FORM A LOOP PORTION IN THE YARN.